High blood pressure

Research into Brazilian pit viper venom produced the first in a new class of medicines to lower blood pressure - angiotensin-converting enzyme (ACE) inhibitors. Snake venoms are extremely complex, each containing as many as 100 different substances, and scientists believe they may yield a wide array of medicines.

People bitten by the snake collapse because their blood pressure drops suddenly and drastically. Once the key components of the venom were isolated, further research established just how they reduced blood pressure in rats.

ACE inhibitors expand constricted blood vessels by preventing the formation of the naturally occurring substance, angiotensin, which raises blood pressure. Sir John Vane, who won a Nobel Prize in 1982, helped to isolate key components from the pit viper venom. Scientists were then able to produce synthetic versions of the chemicals involved.

Once the efficacy and safety of the new medicines were proven in rats and dogs, the new class of ACE inhibitors went into clinical trials in humans and have been helping many millions of people around the world to control their blood pressure. Reducing hypertension may reduce the risk of stroke, heart attack and kidney disease.